Tiger Woods insisted he is not injured after sidelining himself for back-to-back sessions as the United States continue to struggle at the Presidents Cup.

Saturday morning's four-ball contests left seven-time reigning champions the USA trailing Ernie Els' Internationals 9-5 in Melbourne, where Woods sat out.

Despite the USA facing an uphill battle to maintain their stranglehold on the tournament, playing captain Woods again opted to partner Justin Thomas with Rickie Fowler for the afternoon's foursomes.

It came as a surprise, given Woods won consecutive matches alongside Thomas on Thursday and Friday at Royal Melbourne Golf Club.

However, 15-time major champion Woods - who equalled Phil Mickelson's record for most Presidents Cup wins on Friday - told reporters: "You have to do what's best for the team, and I'm getting ready for the singles tomorrow [Sunday]."

"I tried to talk myself out of it, too," added Woods, who denied he is injured. "But you know, it is what it is, and we're going to go out there and try and get some points today and be ready for tomorrow."

Woods' decision to leave himself out of action until Sunday's singles surprised International captain Els - whose team are on track for their first Presidents Cup triumph since 1998.

"Yes, especially the way he's been playing with JT," Els replied when asked if he was surprised by the absence of Woods. "But JT has been a rock-solid on their side, and looks like he's teaming well with Rickie.

"But yeah, I thought Tiger would play this afternoon."